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Filtration Information

The ISO cleanliness code is used to quantify particulate contamination levels per milliliter of fluid at 3 sizes 4µ[c], 6µ[c], and 14µ[c]. The ISO code is expressed in 3 numbers (ex. 19/17/14). Each number represents a contaminant level code for the correlating particle size. The code includes all particles of the specified size and larger. It is important to note that each time a code increases the quantity range of particles is doubling.

Understanding ISO Cleanliness Codes

When setting target ISO fluid cleanliness codes for hydraulic and lubrication systems it is important to keep in mind the objectives that you are trying to achieve. Such as maximizing equipment reliability and safety, minimizing repair and replacement costs, extending useful fluid life, and minimizing production down-time are attainable goals. Once a target ISO cleanliness code is set, following a progression of steps to achieve that target, monitor it, and maintain it should be easy.

Below is the table out of ISO 4406:1999. It shows the code number associated with the contamination level.

contamination level